You may want to call some local gyms to see if they offer any tumbling camps. If you have a university or professional team with cheerleaders nearby....see if you can hire someone to coach you. They would need to help you with jumps, motions, dance, etc. Does the college you'll be attending have a coed cheer squad? You'll need to have some stunt experience too. On you own...just work on being in the best physical shape you can....high endurance is a plus....and ask for advice regarding your physical appearance (cute hair, good make-up, pretty smile, etc.) Good luck.
